HIV/AIDS Flashcards
1
Q
Largest group of persons infected with HIV
A
MSM (48%)
2
Q
__ is a substrate for the Cryptococcal latex agglutination assay
A
Capsular polysaccharide
3
Q
___ is invaluable to dx of Cryptococcus
A
Capsule
4
Q
___ T cells play an especially important role in defense against Candida
A
Candida
5
Q
2 major targets of HIV infection
A
Immune System and CNS
6
Q
2 microscopic findings in brain of AIDS pt with impaired cognition
A
Microglial nodule, Perivascular macrophages
7
Q
2 most common viral pulmonary pathogens
A
CMV, herpes
8
Q
3 AIDS-defining cancers
A
Kaposi Sarcoma, EBV-associated tumors, Cervical cancer
9
Q
3 cancers seen in AIDS patients
A
Kaposi Sarcoma, Non-hodgkin lymphoma, Cervical cancer
10
Q
3 M giant cells
A
Multinucleated, Molded nuclei, Marginated native chromatin (HIV Herpes)
11
Q
3 Viral enzymes in HIV core
A
Protease, RT, Integrase
12
Q
4 most common bacterial pulmonary pathogens
A
P aeruginosa, Mycobacterium, L pneumophila, L monocytogenes
13
Q
4 most common fungal pulmonary pathogens
A
P jiroveci, Candida, Aspergillus, Cryptococcus neoformans
14
Q
Acute Phase is characterized by
A
Nonspecific symptoms, Viremia, Widespread seeding of peripheral lymphoid tissue
15
Q
AIDS CD4/CD8 ratio
A
.5 to 2
16
Q
Approx 90% of HIV infections initially are transmitted by
A
R5 strains
17
Q
Atypic mycobacterium are seen __ in course
A
late
18
Q
B Cells in AIDS
A
Hypergammaglobulinemia and circulating immune complexes; Polyclonal B cell activation
19
Q
Bacterial and tubercular infections of lung are more likely at __ levels of CD4
A
higher
20
Q
Biopsies from enlarged lymph notdes in early stages reveal
A
marked follicular hyperplasia
21
Q
Biopsy of Herpes nodule shows separation where
A
Dermal-epidermal junction
22
Q
Brain equivalent of a granuloma
A
Microglial nodule
23
Q
Candida esophagitis is common among patients with
A
AIDS
24
Q
CD4 count in beginning of crisis phase
A
Below 500
25
Cells affect by CMV in lungs
Alveolar mac's, epithelial, endothelial
26
Cells infected by CMV exhibit
Gigantism of entire cell and nucleus
27
Cells that express CD4
Macrophages, DC's
28
Clear halo around fungi
Capsule --> Cryptococcus
29
Close to 100% of brain lymphomas are __-related
EBV
30
CMV and M. Avium are uncommon until CD4 levels are
below 50
31
CMV infection in AIDS patients is usually
disseminated
32
Common feature of AIDS secondary neoplasms
Tumor cells typically infected by an oncogenic virus
33
Counts below 500 CD4 are associated with
early symptoms
34
Cryptococcus gelatinous masses expanding the Virchow-Robin spaces
Soap-bubble lesions
35
Despite the presence of spontaneously activated B cells, AIDS patients are unable to
mount antibody responses to novel antigens
36
Drop in viremia to low but detectable levels occurs by about
12 weeks after primary exposure
37
During chronic phase, what are sites of continuous HIV replication and cell destruction
Lymph nodes and spleen
38
During clinical latency period, what proportion of t cells harbor virus
small proportion (up to 10%)
39
During clinical latency phase, CD4 drops to
50/cu mm
40
During primary infection (acute phase), CD4 drops to
500/cu mm
41
Entry of HIV into cells requires
CD4 molecule
42
Even without usual conditions, CDC defines any HIV-infected person with CD4 count less than ___ as having AIDS
200
43
Fever of more than 1 month duration, fatigue, weight loss, diarrhea
Crisis phase
44
First types of cells infected with HIV
CD4 T cells in mucosal lymphoid tissue
45
Function of HIV nef gene
Reduces surface expression of CD4 and MHC on infected cells
46
Function of HIV tat gene
Transcription of viral genes
47
Gatekeepers of HIV infection
macrophages
48
HIV is most likely carried to brain by
infected monocytes (R5 types)
49
HIV viral load during clinical latency phase
10,000/ml
50
HIV viral load during crisis phase
10 million/ml
51
How do most children get AIDS
vertical transmission while in utero or newborn
52
Impaired humoral immunity in AIDS patients renders them susceptible to
encapsulated bacteria (S. Pneumoniae, H. Influenzae) that require Ig's for opsonization and clearance
53
Important dx clue for C Albicans
Pseudohyphae --> Budding yeast cells joined end to end at constrictions
54
In addition to CD4, what else must bind for infection
gp120 must bind CCR5 and CXCR4
55
In immunosuppressed patients, cryptococcus fungi grow in
gelatinous masses w/in the meninges or expand the perivascular Virchow-Robin spaces
56
Inflammation response after disease progression
Sparse and atypical
57
intra-alveolar foamy, pink-staining exudate is characterstic of
P Jiroveci
58
Is p17 outside or inside of viral envelope?
Inside
59
Kaposi sarcoma is caused by
KSHV, HHV-8
60
Kaposi sarcoma is more common in what type of AIDS patients
MSM
61
Large cells + basophilic nuclear inclusions w/ halos + granular basophilic cytoplasmic inclusions
CMV infection
62
Largest resevoir of T cells in body
Mucosal lymphoid tissue
63
Leading contributor to morbidity and mortality in HIV-infected persons
Pulmonary diseases
64
Lesion containing spindle cells that share features with endothelial cells and SM cells
Kaposi Sarcoma
65
Lymph nodes after disease progression
Severe follicular involution and lymphocyte depletion --> Hyalinized --> Burnt-out
66
M. tuberculosis manifests itself __ in course
early
67
Macrophages vs T cells containing HIV
Can harbor viruses for much longer due to cytopathic resistance
68
Major mechanism of CD4 T cell loss is
lytic HIV infection of cells, and cell during during viral replication
69
Matrix protein of HIV
p17
70
Microglial nodule
Brain equivalent of a granuloma
71
Microscopically, involved areas of lung in P jiroveci infection demonstrate
intra-alveolar foamy, pink-staining exudate
72
MOA of anti-HIV-1 protease inhibitor drugs
Prevent viral assembly by inhibiting formation of mature viral proteins
73
Most common Candidiasis presentation
Superficial mucosal infection
74
Most common disease-causing fungus
Candida albicans
75
Most common extranodal site in late-stage AIDS of lymphoma
Brain --> Considered AIDS-defining condition
76
Most common form of opportunistic CMV disease
CMV retinitis
77
Most common neurologic dysfunction in AIDS
Progressive encephalopathy (AIDS dementia complex)
78
Most common opportunistic infections other than P. jiroveci
Mucosal candidiasis, CMV, Herpes, M. Tuberculosis and atypical mycobacterium
79
Most common secondary infection of CNS
Toxoplasmosis
80
Most common viral opportunistic pathogen in AIDS
CMV
81
Most HIV sequence variants cluster in parts of the genome encoding
envelop glycoproteins
82
Most readily detectable HIV viral antigen
p24
83
Most sexually transmitted cases of AIDS in US are due to
MSM sexual contacts
84
Most virus particles are found where in relation to follicular dendritic cells
Surface of dendritic processes
85
Non-"opportunistic" bacteral pathogens infecting lungs
S pneumoniae, S aureus, H influenzae and gram negative rods
86
Nonprogressors remain asymptomatic for
10 years: stable CD and low levels virus in plamsa
87
Normal amount of CD4
1000/cu mm
88
Normal CD4/CD8 ratio
1 to 2
89
Normal duration of clinical latency phase
7-10 years
90
Nucleus of CMV-infected cell
W/in nucleus, large inclusion surrounded by clear halo (owl's eye)
91
Outer to Inner: p24, envelope, p17
Envelope, p17 matrix, p24 capsid
92
P jiroveic infection in lung produces
Interstitial pneumonitis
93
People with defective ___ are relatively resistant to developing AIDS
CCR5 receptor
94
Percent of new AIDS cases attributable to MSM contact
<50
95
Pneumocystis jiroveci infection is largely confined to
lung
96
Pneumocystis pneumonia usually occurs at CD4 levels below ___
200
97
Pneumonia caused by __ is presenting feature in many cases
P. jiroveci
98
Predominant cell types in brain infected with HIV
Macrophages, Microglial cells
99
Prominent intranuclear basophilic inclusions spanning half the nuclear diameter set off by clear halo
Owl's eye --> CMV
100
Property conferred by vpr gene
HIV-1 can infect and multiply in terminally diff, nondividing macrophages
101
Pseudohyphae --> Budding yeast cells joined end to end at constrictions
C Albicans
102
Qualitative defects in T cell function
Reduced antigen-induced t cell proliferation; impaired Th1 cytokine production; Abnormal intracellular signaling
103
R5 use what as their coreceptor
CCR5: Macrophages and T Cells
104
Reduces surface expression of CD4 and MHC on infected cells
Function of HIV nef gene
105
Round to cup-shaped cysts in silver stain
P jiroveci infection
106
Silver staining of tissue in P jiroveci infected lungs reveals
Round to cup shaped cysts, often with intracystic bodies but without budding, in the alveolar exudates
107
Soap-bubble lesions
Cryptococcus gelatinous masses expanding the Virchow-Robin spaces
108
Sore throat, myalgia, fever, rash, and sometimes aseptic meningitis
Acute phase
109
Stains effectively highling Cryptococcus
India ink or Periodic acid-shiff
110
Structure of HIV-1
Spherical, contains electron-dense, cone-shaped core surrounded by lipid envelope derived from host cell membrane
111
Symptoms during clinical latency phase
Either asymptomatic or persistent lymphadenopathy, minor opportunistic infections (thrush, herpes)
112
Symptoms of patients with >500 CD4 cells
generally none
113
The immune response against HIV-1 is directed against
the viral envelope
114
The initiation of proviral DNA transcription occurs only when
infected cell is activated by exposure to antigens or cytokines
115
The progression of HIV infection in vivo is dependent on
nef gene
116
The property of syncitia formation is confined to __ strain of HIV
X4
117
Timeframe of Acute Phase
3-6 weeks after infection (50-70% of patients)
118
Transition from acute to chronic phase is characterized by
Dissemination of virus, viremia, development of host immune response
119
Tropism of R5 HIV
Macrophages and T Cells
120
Tropism of X4 HIV
Just T cells
121
Typical adult patient in US presents with
Fever, weight loss, diarrhea, lymphadenopathy, multiple opportunistic infections, secondary neoplasms
122
Typically, AIDS patients present with
Fever of more than 1 month, fatigue, weight loss, diarrhea
123
Unlike in Candida, ___ are not seen in Cryptococcus
Psuedohyphal or true hyphal forms
124
Viral glycoproteins on HIV
gp120, gp41
125
Viral load peak during primary infection (acute)
10 million/mL
126
Virus is most likely carried into brain by
monocytes
127
W/in nucleus, large inclusion surrounded by clear halo (owl's eye)
Nucleus of CMV-infected cell
128
What binds to CCR5 and CXCR4
gp120
129
What does gp120 bind to
CCR5 (macrophages) and CXCR4 (T cells)
130
What has accounted for approx 80% of deaths of AIDS patients
Opportunistic infections
131
What level of CD4 is associated with severe immunosuppresion
<200
132
What percent of patients have clinically evident neurologic dysfunction
40-60%
133
What percent of patients have neurologic involved on autopsy
90%
134
What reflects the onset of immune system decompensation
Persistent lymphadenopathy with significant constitutional symptoms
135
Where are most HIV-infected macrophages found
Tissues, not peripheral blood
136
Which level provides info about direction in which disease is progressing
Viral load
137
With immunosuppresion, mycobacteria do not evoke
granuloma formation
138
X4 use what as their coreceptor
CXCR4: T cells
